Citroen C3 / C5 Aircross Forums

Have checked most of the usual tyre suppliers online, and according to all of them, my C3 Aircross has tyres sized 215/55 R17. (Some say R16) But my current tyres, which are probably original, are 215/60 R17. So what does the 55 and 60 refer to? And does it make a difference that my car is automatic?

I think you've had the wrong tyres fitted in that case!

There were never any 215/55/R17 tyres fitted to the C3 Aircross for that year.

215 X 50 R17 for the 17" Diamond Cut '4 Ever' Wheels.
205 x 55 R16 for the 16" 'Matrix' Diamond Cut Wheels.

The '55' refers to the height of the tire sidewall as the percentage of the nominal section width. More simply put, it's the height/width.

So what happens if it fit 215/50 on the front, and leave 215/60 on the back?

It's never a good idea to mix tyre sizes and patterns. You really should have the same brand, size, tread pattern, load index and speed rating on the front and rear tyres for optimal safety.

Stick to the recommended tyres sizes for the vehicle. If you don't know what should be on there, check your tyre pressure label which is on the passenger side door main pillar. It will state the tyre size right at the top.

the2ems wrote: ↑Mon Aug 08, 2022 8:14 pm So what happens if it fit 215/50 on the front, and leave 215/60 on the back?

Because the rolling diameter is smaller on the front the car will be slifghtly lower at the front than at the back.

How stupid am I. The photo I was looking at to get my tyre size was not even my car Mine are indeed 215/50/R17

I'm just trying to work that one out .... But glad you know what tyres you have on the vehicle now

Quick question. Had my new front tyres today, and booked a fee wheel alignment check. I knew something would need adjusting, because I had quite bad uneven wear on both tyres. They were well down around the outside. So they checked and adjusted the tracking. Is alignment just a posh word for tracking? Also, after he put the front wheels back on, he checked the pressures in the back. I asked him what pressure he was setting at, and he said 33 all round. Like an idiot, I didn’t ask why, because I always go to 36 all round. Maybe because of the hot weather?

They tend to use a standard pressure. On one of my C4 Picassos the tyres should have been ~48psi, but they still put 35psi in. One of the issues is that the pressure is usually set whilst the wheel is off the car, nd as soon as it is refitted and the weight of the car is on the tyre the pressure will increase. When I have anything done my first call is always to a 'petrol' station to check pressures, although I am aware that the gauges may not be particularly accurate.

Again - check you tyre pressure label on the passenger door pillar. It will provide on the diagram the pressures according to how loaded the vehicle is with icons for luggage / passengers so you can see the appropriate pressures.

Always check your tyre pressures when the tyres are cold!